Performance evaluation of low-volume blood collection tubes for coagulation tests

Area of Science:

• Clinical chemistry and hematology
• Diagnostic blood collection technologies
• Patient blood management

Background:

• Frequent phlebotomy for lab tests causes significant iatrogenic blood loss, particularly in critical care.
• Conventional blood collection tubes often exceed analyzer volume requirements.
• Novel microsampling tubes aim to reduce blood loss without compromising test quality.

Purpose of the Study:

• To evaluate the analytical performance of 1 mL vacuum blood collection tubes compared to conventional 3 mL tubes for coagulation testing.
• To assess the potential of microsampling tubes to reduce diagnostic blood loss.
• To ensure test quality is maintained with reduced blood volumes.

Main Methods:

• Systematic comparison of 1 mL microsample tubes with 3 mL tubes following CLSI EP07 and WST 224-2018 guidelines.
• Evaluation of aspiration volume accuracy, result comparability for six coagulation parameters, and interference resistance (hemolysis, icterus, lipemia).
• Coagulation parameters tested: APTT, PT, TT, FIB, D-dimer, ATIII, using Passing-Bablok and Bland-Altman analyses on a CX9000 analyzer.

Main Results:

• Aspiration volume deviation was comparable between 1 mL (4.0%) and 3 mL (4.9%) tubes, both within the ±10% tolerance.
• High concordance was observed between 1 mL and 3 mL tubes for all six coagulation parameters (slopes 0.931-1.051, non-significant P-values for linearity).
• Bland-Altman analysis confirmed that all coagulation parameters met predefined clinical consistency criteria.

Conclusions:

• 1 mL vacuum coagulation tubes demonstrate equivalent analytical performance to 3 mL tubes for six routine coagulation parameters.
• These microsampling tubes offer a reliable, blood-conserving solution, reducing blood draw volumes by over 50%.
• Implementation is particularly beneficial for critical care, pediatrics, and other patient populations requiring minimized blood collection.